Charged particle detectors are employed in charged particle beam system to generate an electrical output signal based on charged particles leaving a sample surface due to impinging primary charged particles. By scanning the primary charged particle beam across a sample surface and recording a signal based on charged particles leaving the sample surface in dependence on the position of the impinging primary charged particle beam an image of the sample surface can be generated. If such images are recorded based on different species of charged particles leaving the sample surface, such as for example secondary electrons and secondary ions, images with different contrast characteristics can be formed.
Charged particle detecting devices being capable to detect electrons as well as ions are for example disclosed in EP 1636819 A2, EP 1365260 A2 or EP 2297763 A2. The disclosed charged particle detecting devices include an ion-to-electron converter as well as a detector which generates an electrical output signal if electrons impinge on an electron-sensitive surface of the detector. If electrons are to be detected a control electrode is biased with a voltage that the electrons directly impinge on the electron-sensitive surface of the detector. If ions are to be detected, the control electrode is biased with a voltage so that ions impinge onto the ion-to-electron converter; the electrons emitted by the ion-to-electron converter are thereafter detected by the detector.